Usage

Basic usage

Encode a string in a QR code
qrtool encode "QR code" > output.png
Output
Figure 1. Generate this image
Decode a QR code from this image
qrtool decode output.png
Output
QR code

SVG generation

Use -t option to change the format of the generated image. The format is png (default), svg or terminal (to the terminal as UTF-8 string).

qrtool encode -o output.svg -t svg "QR code"
Output
Figure 2. Generate this image

Micro QR code generation

Use --variant option to change the variant of the generated QR code. The variant is normal (default) or micro (Micro QR code).

qrtool encode -v 3 --variant micro "QR code" > output.png
Output
Figure 3. Generate this image

Colored output

Use --foreground and --background options to change the foreground and background colors of the generated image. These options takes a CSS color string such as brown, #a52a2a or rgb(165 42 42). The default foreground color is black and the background color is white of CSS’s named colors.

qrtool encode --foreground brown --background lightslategray "QR code" > output.png
Output
Figure 4. Generate this image

Supported input image formats

qrtool decode supports decoding a QR code from the following image formats

To support decoding from SVG image, the decode-from-svg feature must be enabled at compile time. Note that the SVG image is rasterized before scanning.

Image formats other than PNG can be disabled by disabling the default feature, and can be enabled individually.

Use -t option to specify the image format. If this option is not specified, the image format is determined based on the extension or the magic number.

Input
Figure 5. Input this WebP image
Decode a QR code from the WebP image
qrtool decode input.webp
# or
qrtool decode -t webp input.webp
Output
QR code

Generate shell completion

--generate-completion option generates shell completions to stdout.

The following shells are supported

  • bash

  • elvish

  • fish

  • nushell

  • powershell

  • zsh

Example
qrtool --generate-completion bash > qrtool.bash

Integration with other programs

Both qrtool encode and qrtool decode can read from stdin and output to stdout.

Optimize the output image

The image output by qrtool encode is not optimized. For example, a PNG image is always output as the 32-bit RGBA format. If you want to reduce the image size or optimize the image, use an optimizer such as oxipng or svgcleaner.

Optimize the output PNG image
qrtool encode "QR code" | oxipng - > output.png
Optimize the output SVG image
qrtool encode -t svg "QR code" | svgcleaner -c - > output.svg

Reading and writing unsupported image formats

If you want to save the encoded image in an image format other than PNG or SVG, or decode an image in an unsupported image format, convert it using a converter such as ImageMagick.

Read Cargo.toml from stdin and save the encoded result as a JPEG XL image
cat Cargo.toml | qrtool encode | magick png:- output.jxl
Decode this image and print the result using bat
magick output.jxl png:- | qrtool decode | bat -l toml
1. CUR is also supported.
2. SVGZ is also supported.